The present invention relates to sheet stacking and weighing devices and more particularly to an automatic hydraulic stacking and weighing system. Sheets of paper, pulp, plywood, etc. are conveyed from a sheet cutter by a conveyor and are stacked one on top of the other on a stacking table. The stacking table is indexed downwardly as sheets are assembled thereon until a full stack of sheets has accumulated - determined either by stack weight, stack height or sheet count.
Different types of systems are and have been used to perform this stacking and weighing operation. Some of these systems are completely mechanical in nature while others employ hydraulic systems, a plurality of hydraulic cylinders or electro-mechanical mechanisms. These known systems have a number of drawbacks. Completely mechanical systems are cumbersome and require constant maintenance due to the large number of moving parts such systems require. Hydraulic systems employing a plurality of hydraulic cylinders also require maintenance and are hard to control since one cylinder may tend to index more than the others. Electro-mechanical systems also require high maintenance since an electric motor must be started and stopped many times in indexing to a full load of sheets.